Expose model parameters in UI (temperature, max_tokens, etc)

[scosman]

Add UI to expose setting (and persisting) model parameters.

[scosman]

I did this for fine-tuning in a really nice way. We should reuse that style/code when doing this.

[sammcj]

num_ctx for Ollama would probably make sense to have as an optional parameter.

For context (pun intended) - by default Ollama models from the public hub come configured with a tiny little 2k context which is only usable for very small tasks, similarly sometimes you'll create your models with a much larger default context size than what is efficient for dataset generation tasks and you might want to reduce this down to something reasonable like 4k-8k to keep the performance up.